Antibacterial effect of six plant extracts on some pathogenic bacteria

Introduction: According to side effects of chemical drugs, recently much attention has been paid to plants as a drug. The present study aimed to determine the antibacterial effect of six plant extracts on some pathogenic bacteria.
Materials and Methods: In an experimental study, at first the six plant extracts including Cinnamon, Turmeric, Thyme, Peganum harmala, Citrus aurantium and Achillea were prepared. Next, with regard to the minimum Inhibitory concentration (MIC) and standardized broth micro dilution method concentrations of each extract successively 62 to 12000 μg/ml prepared and then a 0.5 McFarland unit concentration of eight bacteria including standard Staphylococcus aurous (standard strain), Pseudomonas aeruginosa, Staphylococcus aurous, Enterococus Faecium, Escherichia coli, Salmonella typhi, Shigella dysenteriae and Klebsiella Pneumonia was obtained. The prepared compound was diluted back to 1 in a thousand.
Results: All the extracts were able to inhibit the growth of all bacteria. In general, Peganum harmala and Turmeric were the most inhibitor so that their MIC against shigella dysenteriae was 62 and 125µg/ml, respectively. Cinnamon was the third against shigella dysenteriae and the standard Staphylococcus aurous strains at a concentration of 1000 µg/ml. Achillea, Citrus aurantium and Thyme had not a considerable inhibitory against all bacteria.
Conclusions: In general, Peganum harmala, Turmeric and Cinnamon had a higher antibacterial activity and can be used as a food preservative and a drug compound for treatment.